Crimthann Srem mac Echado
Crimthann Srem mac Echado, also known as Crimthann Feimin, was a King of Munster from the Eoganachta dynasty in the early 6th century. He was the son of Eochaid mac Óengusa and grandson of the first Christian king of Munster, Óengus mac Nad Froích.
The Annals of Tigernach record him succeeding his father and becoming king of Munster in 522. According to the Laud Synchronisms, he ruled for twenty years, which places his death at 542. The record of 6th-century kings in Munster is obscure and the Laud Synchronisms may have been written to favour his dynasty. The saga Senchas Fagbála Caisil omits him from its list of kings while the list in the Book of Leinster includes him.
He was the ancestor of the Eoganacht Glendamnach branch of the family. He had five sons including Coirpre Cromm mac Crimthainn, a king of Munster. The genealogies give him a twin brother Crimthann, son of a woman named Dearcon, who was an ancestor of the Airthir Cliach branch. It is possible that the genealogies created two separate Crimthanns. In which case he would be the Crimthann, son of Dearcon mentioned in a tract relating to a Munster synod in the 6th century